Category : Anatomy

The distal biceps muscle is located in the front of your arm (see image above). This muscle helps you to bend your elbow and twist your forearm. Unfortunately, the biceps is prone to injury, especially the biceps tendon, which connects the bicep muscle to the radius bone in your forearm. This tendon can weaken over time, which is called tendonosis. If you have tendonosis of the biceps tendon, you may feel a dull or sharp pain just past the elbow in the forearm. There’s also a chance that you will feel no pain.

Tendonosis can sometimes lead to a tear or rupture in the tendon. Tears or ruptures can happen when you are lifting something heavy such as furniture or weights.

Some signs that you may have torn or ruptured your biceps tendon include:

Arteries are muscle-lined tubes in the body that transport blood from the heart to other parts of the body. In the upper extremity, there are two arteries that pass through the axilla, also known as the “armpit.” These arteries are:

Subclavian Artery: This is the large vessel that begins the blood supply to the upper extremity. It begins near the heart and travels under the clavicle bone toward the shoulder. Eventually it turns into the axillary artery.

Axillary Artery: This is a continuation of the subclavian artery. This artery travels deep in the arm pit, feeding muscles and bones around the shoulder with its branches. It eventually turns into the brachial artery.

Tendons are fibrous cords that are similar to a rope, attached to muscles and bone. The tendons that control movement in your hands, wrists and fingers run through your forearm. There are 6 tendons that help move your wrist. The wrist tendons are:

Flexor carpi radialis: This tendon is one of two tendons that bend the wrist. It attaches to the base of the second and third hand bones. It also attaches to the trapezium, one of your wrist bones.

Flexor carpi ulnaris: This is the other tendon that bends the wrist. It attaches to the pisiform, another wrist bone, and to the 5th hand bone.

Palmaris longus tendon: This tendon is unique because only 3/4 of the population has it. For those who do have it, it can vary in size. It is, however, a tendon you can live without because it has very little function in the hand and wrist. This tendon is often used to repair other tendons since it serves such a small purpose.

Joints are cartilage surfaces that connect bones to each other. This cartilage allows our bones to glide smoothly against one another, allowing us painless movement. There are four joints in each finger, totaling 20 joints in each hand!

The small, ringer, middle and index fingers all have the same four joints:

Distal Interphalangeal Joint (DIP): The DIP joint is located at the tip of the finger, just before the finger nail starts. Arthritis can develop at this joint, and it is also commonly fractured.

Proximal Interphalangeal Joint (PIP): The PIP joint is the joint just below the DIP joint. It is located below the top two bones of the finger and allows the finger to bend and extend. This joint can become stiff easily after injury.

Metacarpophalangeal Joint (MCP): The MP joint is where the hand bone meets the finger bone, referred to as the “knuckle.” These joints are very important, allowing us to bend/flex and spread our fingers.

Carpometacarpal Joint (CMC Joint): The CMC joint is located at the bottom of the hand bone. This joint varies in each finger. For example, in the index finger, it has little motion. In the small finger, it has a lot of motion. Injuries and problems with this joint are uncommon.

The thumb joints are a little different than the other finger joints. To learn more about the thumb joints and more about the finger joints, visit our online Anatomy section.

There are five major bones in the shoulder. The shoulder bones can easily be affected by falls or accidents, in addition to arthritis. Here is an overview of the shoulder bones:

Scapula: Another name for this bone is the shoulder blade. There are 17 muscles that attach to the scapula! Much of your shoulder motion is between the scapula and the chest. The scapula is part of the “shoulder girdle” which also includes muscle and ligament that allow your shoulder to move.

Clavicle: This bone is also referred to as the collar bone. The clavicle connects the arm to the chest. It has joints on both ends, which can become arthritic.

Acromion: This bone is a flat projection of the scapula that gives the shoulder its square shape.

Coracoid Process: This bone is also a projection of the scapula. It points outward toward the front of the body. This bone is important because its muscles and ligaments help support the clavicle, shoulder joint and humerus.

Glenoid Cavity: This is the socket portion of the ball-and-socket joint of the shoulder. Any abnormalities in the cavity can cause joint instability, which can lead to a condition called “frozen shoulder.”

The wrist muscles and forearm muscles do so much more than give you strength in your arm and wrist. These muscles also play a part in helping you move your hand and fingers. There are 18 different muscles!

The wrist joints lie between the many different bones in the wrist and forearm. Many wrist injuries (such as fractures, also known as a broken bone) involve the joint surface. There are three joints in the wrist:

Radiocarpal joint: This joint is where the radius, one of the forearm bones, joins with the first row of wrist bones (scaphoid, lunate, and triquetrum).

Ulnocarpal joint: This joint is where the ulna, one of the forearm bones, joins with the lunate and triquetrum wrist bones. This joint is commonly injured when you sprain your wrist. Some people are born with (or develop) an ulna that is longer than the radius, which can cause stress and pain on the joint, known as ulnocarpal abutment (impaction) syndrome.

Distal radioulnar joint: This joint is where the two forearm bones connect. Pain with this joint can sometimes be a challenging problem to treat.

Learn more about the joints of the wrist and also the bones of the wrist in our Anatomy section. You can also visit www.HandCare.org for information on conditions and injuries of the hand, wrist, arm and shoulder.

Carpal tunnel syndrome is a common condition affecting the hands. Patients typically say that they wake up at night with a feeling of pins and needles in their fingers, like their hand is asleep. They commonly shake their hands out to relive the symptoms. As the problem progresses, their hands will go numb when they drive, talk on the phone, or do their hair. As the problem becomes more severe, they will eventually report constant numbness in their fingers.

All of the nerves that go to the hand originate from the spinal cord at the neck level. The median nerve goes down the arm and crosses the wrist under a ligament called the transverse carpal ligament. This nerve then gives sensation to the thumb, index and long finger, as well as half the ring finger. Watch this 2-minute animation to learn more about how carpal tunnel affects your hand.

The HandCare Blog is managed by the American Society for Surgery of the Hand, the oldest and most prestigious medical specialty society dedicated to the hand and upper extremity. Visit www.HandCare.org for more information about conditions, injuries and treatment of the hand, arm, elbow and shoulder.